Method of treating rubber compositions



1933. A. SZEGVARI METHOD OF TREATING RUBBER COMPOSITIONS Original Filed 001;. 6, 1927 PatentedAugF-ZQ, 193s it I I I 2 76 I UNITED-S 'I;' ATES {PATENT a 1,924,576 METHOD OF TREATING- RUBBER COMPOSITIONS' i Andrew" Szegvari, Akron; Ohio, assignor to] .American Anode, Inc, Akron, Ohio, a corpora-f tion of Delaware I Continuation of application Serial No. 224,505, October 6, 1927. .This application January 9, L

1931; SerialNo. 507,721, 7 v, Y a

'z clai s. (ci ia- 5o) p p This invention relates to a method of treating operative method of applying a pervious ma rubber compositions formed by deposition'from terialwith the compacting pressure to ailayer of aqueous dispersions thereof and more particularrubber composition deposited from' an aqueous r lytothe're'moval in large part of the liquid condispersion thereof is shown,"it being understood stituents of a layer of a rubber composition of that the meansrdisclosed in (the drawing are 59 the character hereinabove indicated. merely 'illustrative'of theprinciple ofthisinizen- "It hasbeen heretofore proposed to deposit from tion, which is, however, in no way limited to the a natural or artificial aqueous dispersion of rubmechanism shown in the drawing, andinwhich Wm ber'upon a form or other foundation member, the figure is a planview of an apparatus adapted 6O which may be either of porous or non-porous for thepracticeof my invention" with the rubber j material, a layer or body of rubber bydipping', composition to' be treated deposited uponLa cylinsuction, electrodeposition, spraying, spreading dricalfl form. i a and other well known layer forming processes. In the drawing, there is shown a means. for The deposits formed from such rubberdisper treatinga rubber layer 10 'freshlydeposited irom.. 5 sions are ordinarily coagulated' as layers of a more an aqueous dispersion thereof upon a cylindrical or less firm irreversible c'oagulum, either bythe tubular form or mandrel 11, such as may be usedelectrolytic action of the current employed in 'in'th'e manufactureof inner tubes for pneumatic electrodepo'sition, or, by a coagulant substance vehicle'tiresor for'makingof rubberband stock. such as anacid or a coagulatingsaltconstituting It will be understood, however, that theiorm ll c a portion of the form or'applied to the surface of may be of other shape and proportions andthat the layers of the dispersion on the form, or by it may be solid as well ashollow and of porous' other"means. The layers or bodies of composie material if desiredlgk, f j tion formedin any of these ways contain a large As shown, the mandrel 1 1is mounted for rota-' amount of "liquid, for the most part water, which tion upon its ownaxis in any suitable apparatus, needs be removed from the layeror -body prior to it being illustratedrherein as supported from its Tvulcanization if dense, homogeneous and uniform ends in the tail-spindle 12 and in the drivingproducts are to be obtained; l 7 head 13 of a machine resembling a lathe in con- The object of this invention is to provide a 'struction. A fixed bar 14' is positioned adjacent method for the manufacture of rubber goods diand parallel to the mandrel'll to serve asa retly from aqueousdispersions, in which method guide ,for' thepervio'u's -materia1 15, such as' a alarge part ofthe'liquid content oi a deposited woven fabric strip, employed to place the rubber layer'of a rubber composition of thecharacter layer 10 under compression.- i V, hereinabove indicated may easily and quicklybe- In carrying out my invention the mandrel 11' removed. j i with its freshly deposited composition of rubber In carrying out this invention, a freshly de- 10 is mounted with itsends supported in the tailposited layer of a rubber composition formed spindle 12 and the, driving-head 13;,respectively. from an aqueous dispersion of the rubber compo- .The end of the pervious strip material 15 :is sition is subjected to a uniform compacting prespassed under the bar 14, and then'secured'to the sure by the application thereto of a pervious mamandrel 11 at one endthereof, as by making ini- 9O terial, the pressure preferably being applied in tial overlapping turns about the mandrel in such such manner as not materially to disturb the relamanner as to completely overlie the deposit 10 tive positions of the' particles of rubber composiat that end of the mandrel. The drivinlg head 13 I tion one to anothenexcept to bring them into is then set inmotion'to rotate the mandrel and closer contact by the compacting pressure' It is to draw the strip 15 thereonto, a supplyroll 16 obvious that the pervious material employed to for said strip material beingmoved longitudinalapplythecompacting pressure may be any one-of 1y of the -m'a'ndrel so that the" strip 15 is laid v a number of water permeable or porous materials thereon in -overjlapping helical Convolutions, The and that the compactin'g pressure maybe applied withdrawal of the strip 15 from its supplyroll 1'6 in a varietyoi ways. V is'retarded, as-by braking'actionat the supply In the accompanying drawing an industrially roll and a snubbing efl'ecton the bar 14 so that? the strip is laid on the deposit under a considerabletension and exerts a substantially inwardly and radially directed'compacting force upon the deposit 10. Due to the tension with which the strip is wound upon the deposit 1!) it continues to'exert a compacting or squeezing pressure which forces the moisture from the'deposit 10 outthrough the 'pervious strip 15, the liquid collecting on the exterior thereof where it ma'y drip mandrel, it will be obvious that some of the liquid.

15- dation material. The deposited rubber, being altherefrom', or'if desired, may be wiped therefrom by the application of an absorbent materiah If the deposit 10 is formed upon a porous form or of the deposited rubber composition will be forced into and through pores orforamin'a of the foun ready coagulated, is'not capable of penetrating .other. y

' The separation of the liquid 'fromthe solid the meshes or pores of the perviousfmaterial, the rubber particles instead beingbro'ught into closer and more intimate relationship: with one anconstituents of the rubber deposit is accomplished for the most part very quickly afterthe application of the compacting pressure. The pervious strip 15. may however; be allowedto remain in pressure contact'with the deposit for'some time, as until little or no further liquid exudes from the deposit. lnpractice, a single wrapping of the .pervious material-removed'from the deposit immediately or shortly after its application, serves to express the water and compact the rubber suiii ciently for manufacturing purposes. I

'In processes involving the principles of this invention, namely, the application of a compacting pressure to a rubber composition fr'eshlydeposited from an aqueous 'dispersionflthereof by means of a pervious material, a notable improvement in the density, homogeneity strength, and

49 other qualities of "the rubbercomposition layeris produced. Thus, the compacting force of the 1 perviousmaterial so consolidates and amalga-' imates the solid particles of the deposit ,lOthat it may be stripped immediately from the mandrel 11 without any material permanentdeformation.

Incommercialope'rations the application of the pervious 'material with compactingpressure to deposit 10, the removal of the pervious material from the compacted deposit and the stripping of the compacteddepos'it' from the mandrel may be carried out in close successionij' The liquid re,- maining'in the de'posit'is normally removed by evaporation, as by exposing the deposit to 'a current of warm air, afterwhich the deposit is ready for vulcanization whichmay be carried out, by any of the well known processes of vulcaniz ation'. I i

While it has been found thata single applicationof compacting pressure by themethod herein escribed is-ge'nerally suiiicient, for industrial manufacturing operations, in certain cases the application of the compacting pressure may be repeated one-or more times, or a number of-layers of thepervious'compacting material may be successively applied one to the other. It has been found,,ho'wever, that where an adequate con}- pacting pressure is appliedby any of the hereinabove described'processes that; subsequent applications of compacting pressure ,does not sufficiently add to the quality of the product or re.

iducethe amount of, its content to make ,it .ingeneral an economically commercial variw tion-oftheprocesses hereinbefore described, although'it may be useful in some special cases.

- *ln addition to the advantages v herein above,

its shape.

,pervious material.

noted, including thereduction of the "time required for the manufacture of articles or materials of rubber compositions deposited from aqueous dispersions thereof'and improvement in thestrength and properties of such articles and materials, my process has another'secondary and distinctive advantage in that. it enables the forms on which the deposit is made to bereleased quickly for use in subsequent depositing operations and, where metal forms are'employed, in that it minimizes the corrosive effect'of certain constituents of the deposit upon the forms, which constituents are found to be present to some extent in all vulcanizable rubber compositions. It

is obvious that thelatter advantage results in the'reduced length of time required for cleaning the forms prior to. another operation, in' less wastage of metal in cleaning the forms thus prolongingjtheir useful life, and also obviates any extensive contamination of the rubber composi-j. tion dueto the corrosion of the forms while the deposit is in contact therewith; a

The term rubber composition is used herein in a generic sense to indicate caoutchouc, balata,

gutta-percha and other rubber-like materials,

whether in a vulcanizable orv vulcanized conditionand whether .or not admixed with pigments,

fillers, vulcanizing agents, etc. .1

It will'be obvious to those skilled in the art that numerous -modifications and variations in the above described process may be made without departing from thenprinciple of the; invention m herein'set forth; andI "do not, therefore, desire.

to limit the claims hereoi to the specificprocess herein described, This applicationis a continuation of my, co-

pendingapplication Serial;No..2 2l,505, filed Oeto;

position from an aqueous dispersion thereof upon material with. compacting pressure aroundthe rubber composition While still on the mandrel.

4. .The method of treating a rubber 'composi .tion which comprises coagulating a layer ofthe composition upon a foundation member'from an a cylindrical mandrel, andwrapping a 'pervious aqueousdispersion of such composition, applying v a pervious material to the deposited rubber-composition with a? compacting pressure, removing the pervious material, removing the treatedlayer from the foundation member,'--and dryingitl I 5. The method of treating a rubber composition which comprises coagulating alayer of. the composition from .an aqueous dispersion thereof- 1 upon a cylindrical mandrel, andwrappinga per;- vious material with compacting pressure thereon from one end to theother of the composition 6. The method oi treating a 'rubber composition which comprises electrodepmiting; a coag' 7. The method of treating a rubber composition which comprises electrodepositing a. coagulated layer of the composition roman aqueous",

progressively wrapping a woven vfabric. about the:

rubber composition from one endto the otherunder such tension as to-eizert a substantial com pactii'ig pressure; unwrappingfl the fabric, 132- moving the treated layer from' the mandrel, a dryingit. it v sz EGv rIY; i

dispersion thereof upon acylindrical mandrel. 

